Enzymatic hydrolysis as a sample pre-treatment for titanium dioxide nanoparticles assessment in surimi (crab sticks) by single particle ICP-MS.

Author(s) Taboada-López, M.Vanesa; Herbello-Hermelo, P.; Domínguez-González, R.; Bermejo-Barrera, P.; Moreda-Piñeiro, A.
Journal Talanta
Date Published 2019 Apr 01

A reliable sample pre-treatment based on enzymatic hydrolysis has been fully optimized and validated for TiO NPs isolation and determination/characterization in surimi (crab sticks). Efficient extractions have been found when using a pancreatin/lipase mixture at pH 7.4 and 37 °C for 12 h under continuous stirring. The proposed sample pre-treatment procedure has been found not to change TiO NPs size distribution, therefore guaranteeing TiO NPs integrity. TiO NPs determination (TiO NPs concentration) and TiO NPs characterization (size distribution) were assessed by single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) working with dwell times in the microsecond range (high frequency of data acquisition). Method validation was performed for TiO NPs concentrations and TiO NPs sizes. Good repeatability (25% and 8% for TiO NPs concentration and TiO NPs most frequent size), and sensitivity (limit of detection of 5.28 × 10 NPs gfor TiO NPs concentrations, and 31.3-37.1 nm for TiO NPs size) were obtained. Accuracy, calculated through analytical recovery was adequate. Recoveries for TiO NPs standards of 50 and 100 nm were 108 ± 5 and 105 ± 4%, respectively. The proposed methodology was applied to several surimi samples for assessing TiO NPs concentrations and size distribution. Some surimi samples were found to contain TiO NPs (concentrations from 1.40 × 10 to 1.19 × 10 NPs g). TiO NPs size distributions were very different among the samples, and some of them showed wide size ranges (the most frequent size varied from 53.8 to 62.1 nm; whereas, the mean size values were within the 73.4-217.5 nm range).

DOI 10.1016/j.talanta.2018.11.023
ISSN 1873-3573
Citation Talanta. 2019;195:2332.

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